Valve actuating mechanism



o. Hf BANKER VALVE ACTUATING MECHANISM Filed'auly 24, 195s Patented July9, 1940 STATES PATENT orma 7 Claims.

The 'invention relates generally to a valve actuating mechanism for aninternal combustion engine and more particularly to the valve lifter ofthe actuating mechanism.

A general object of the inventionl is to provide a valve actuatingmechanism of new and improved construction rendering the mechanismextremely quiet under all operating conditions, economical tomanufacture, efficient, durable, and

easy to install either initially or as a replacement for no isy, worn orobsolete mechanism.

A more particular object is to provide a valve actuating mechanism ofnew and improved construction in which metal to metal contact blows areeliminated, thereby avoiding the noise and .the periodic vibrationincident to such blows.

Another object is to provide a valve actuating mechanism having a twopart valve lifter, one part being maintained in constantengagement V2Owithrthe valve stem and the other part being maintained in constantengagement with the valve actuating cam and the parts having a new4 andimproved cushioned engagement of large area, assuring long life of thecushioning material and ready separation of the engagement so that theparts will be maintained respectively in engagement with the valve stemand the cam.

Other objects and advantages will become ap- .parent from the followingdetailed description taken in connection with the accompanying drawing,in which:

Fig. 1 is a view, partially in section, of a valve actuating mechanismfor an internal combustion engine embodying the features of theinvention.

Fig. 2 is a diametrical section of the valve actuating mechanism shownin Fig. 1.

Fig. 3 is a diametrical sectional view of a modified form of the valvelifter of the valve actuating mechanism.

Fig. 4 is a fragmentary diametrical sectional view of still anothermodified form of valve lifter. While the invention is disclosed in thedrawing and will hereinafter be described as embodied in three forms ormodifications, it is not intended that the invention be limited to thespecific embodiments disclosed, but it is intended to cover allmodifications and alternative constructions falling Within the spiritand scope of the invention as defined by the appended claims.

-Referrlng to the drawing, particularly Fig.l l, I0 represents thecylinder block of an internal combustion engine and I I represents avalve having a valve head I2 controlling a port opening into a cylinderofthe engine. The valve is (Cl. 12S-90) mounted in the usual manner withits stem I3 projecting slidably through a sleeve bushing Ill secured inthe cylinder block I0. At the` end remote from the valve head, the valvestem carries a washer. I5 between which and the cylinder block 5 I0 acompression spring l6'is interposed to urge the valve toward seatedposition. The valve is opened against the action of the spring I6 atproper intervals by means of a cam Il formed on a cam shaft I8 andacting through a valve 10 lifter generally designated I9. The valvelifter is guided for longitudinal reciprocatory movement in a bore 20formed in a portion of the cylinder block Ill.

Herein the valve lifter is of unique construc- 15 tion designed tosilence the operation of the valve mechanism. Generally, the valvelifter comprises afirst part generally designated 2| maintained incontact with the cam shaft I8, a second part generally designated 22maintained in 20' Contact with the-valve stem and a cushioning meansinterposed between the parts so as to avoid metal to metal impact blowsduring the operationof the engine. The parts have a joint movementtounseat the valve and a slight move- 25 ment relative to one another inorder at all times to .maintain the parts in contact with the cam shaftand the valve stem respectively and to provide the clearance necessaryto take care' of expansion of the valve mechanism caused by 30 changesin engine temperature.

In the form of the .valve lifter shown in Fig. 2 the first or cammechanism operated part 2| comprises a cylindrical main body portion 25having a longitudinal bore 26 opening through the end remote from thecamshaft I8 and a reduced neck 2'I at the same end. Mounted on the neckend of the mainbody portion 25 is a Icupshaped member 28 having a hubportion 29 tting over the neck 21 and by means of which the 40cup-shaped member is secured'by a press fit to the main body portion 25.Disposed within the cup-shaped member 28 is a metallic washer 3U weldedthereto as indicated at 3l and having a central aperture coinciding withthe bore 26 of 45 the main body portion. For a purpose which will becomeapparent hereinafter, the cup-shaped member 2B is of substantialdiameter, larger even than the diameter of the main body portion 25 landseveral times larger than the diameter of 50 f the valve stem I3.

The second or valve mechanism operating part 22 of the valve lifter,consists of a disk-like cap 34 having a cylindrical guide portion orplung r 33 sliclabley in the bore 26.v The cap 34 is pre 5c erablyslightly less in diameter than the inner diameter of the cup-shapedmember 28, and has a boss 35 extending axially therefrom for engagementwith the valve stem. At the inner end the plunger is reduced at 38 toprovide a seat for one end a compression spring 3l dis-v 'maintains themain vvbody portion or cam shaft part in contact with the cam shaft |8and the cap or valve stem part in contact with the valve stem i3. Spring3l, of course, is weaker than spring I6.

Interposed between the parts 22 and 2| and herein in effect forming aportion of the cam operated part 2| is a cushioning means of nonmetallicmaterial mounted in the member 28 and arranged to engage the cap 34 andthereby limit the approaching movement of the parts 2| and 22. Thiscushioning means takes the form of an annular washer 38 of a compositionwhich is resilient and slightly yieldable but substantiallyincompressible volumetrically so that in order to yield in one directionor be compressed in part it must have space to expand in anotherdirection or in another part. The resilient qualities are similar tothose of rubber, but preferably the composition also does notdeteriorate when exposed to heat and oil, a suitable composition beingthe commercial product known as Duprene, which is a product made fromcoal having some of the'characteristics of rubber.

As illustrated in Fig. 2 the washer 38 fits snugly in the cup-shapedmember 28 so that it cannot expand radially, and the adjacent sides ofthe cap 34 and the washer 38 are formed so as to provide space intowhich a portion of the composition of the washer may expand when anotherportion of it is compressed longitudinally. Preferably, one of the partsis beveled or otherwise formed relatively to the other so that therewill be a gradually increasing area of contact between the parts as thevalve lifter is actuated to unseat the valve. Herein the cap 34 isbeveled and the adjacent surface ofthe washer 38 is at. Such graduallyincreasing contact results from the relative movement of the parts 2|and 22 from the upward distortion of the Outer portion of the washer 38under such movement. This assures that the engagement of the parts willbe gradual and not a sudden impact,

and nevertheless the extent of the movement of the parts toward eachother is limited definitely by the space into which a portion of thewasher may expand.v Moreover, the large contact area of the washer 38(it being many times that of the valve stem I3), assures that thepressure per unit area is low enough so that the washer will have a longlife. 'Ihe beveled underneath surface of the cap alsoassures thatthe capand the washer 38 Iwill again separate as the valve is returned toseated position and will not be held together by any suction-cup action.

Positioned between the annular washer 38 and the bottom of thecup-shaped member 28 are a plurality of shims 39 which preferably are ofdifferent thickness so that by the employment of different combinationsthe desired clearance i'n the valve mechanism may be obtained. Thisclearance is of an orderl of a few thousandths of an inch when theengine is cold resulting in a slight space between the cap 34 and washer38 as shown in Fig. 2. As the engine warms up, however, this space maydisappear and the under portion of the cap 34 always bears upon thewasher 38. Under such a condition, the resilient and yieldable characterof the washer 38 still assures proper seating ofvalve by the spring i6.

It will be apparent from the foregoing thaty the spring-3l maintains themain body portion 25 and the cap 34 respectively in contact with the camI1 and the valve stem I3 and that the clearance provided to compensatefor expansion of the valve mechanism appears between the Aparts of thevalve lifter and not between the valve lifter and the valve stem. Thus,with the parts of the valve lifter constantlyv in engagement with thecam and the valve stem respectively, there are no metal to metal impactsat those points. The entire impact resulting from the rapid movementimparted to the valve lifter by the cam l is taken between the washer 38and the cap 34, and thus is cushioned and silenced both because of theresilient character of the washer 38 and because of the beveledunderneath surface of the cap 34 causing a gradually` increased area ofcontact between the washer and the cap.

Fig. 3 shows a modied form of valve lifter in which'a cam operated part2|' is formed partly by a cylindrical member 25 having a bore 26'therein opening through the end remote from the cam shaft. The secondpart 22 is formed by a cap 4| having a diameter substantially equal vthecap will not stick. The cushioning means interposed between the twoparts of the valve lifter herein comprises a plurality of annularwashers 38' of a resilient but substantially incompressible compositionnot affectedy by heat and oil, such as the commercial product known asDum-ene. These washers have an outer diameter substantially equal to thediameter vof the bore 26' and an inner diameter substantially equal tothe diameter of the stem 42.

Interposed betweenv the washers 38' are a pluralityof shims 38 having anouter diameter which is less than -the diameter of the bore 26'. As aresult, a plurality of spaces 44 are formed into which the compositionof the washers 38 may expand when the washers are placed undercompression during the unseating of the valve by the valve lifter orupon expansion of the valve mechanism. The total distortion of thewashers 38 into the spaces 44 is comparable to the clearance to bemaintained in the valve mechanism when cold. In this forml the washers38' serve the dual function of separating the main body portion 25 andthe cap 4| to maintain them respectively in contact with the camshaftand pression of the washers 38 in case of deterioratil which maynot be exceeded during the unseating of the valve by the valve lifter.

tions thereof.

Fig. 4 shows a form of valve lifter embodying the features of thisinvention which is particularly well adapted for substitution inexisting' valve actuating mechanism for it entails the replacement of asmaller part of the mechanism than does the form shown in Figs. 1 to 3.To that end a cup-shaped member 28 is formed -with an axial tubularextension A5 which is received within the threaded end of a standardvalve lifter body portion 25". A washer d5 may be inserted above thebody 25" as shown to strengthen the bottom of the cup-shaped member. Thecup-shaped member 28 thus may readily replace the adjusting screw andlock nut normally threaded into the body portion 25" to provide foradjustment of the clearance normally maintained in the valve actuatingmechanism.

The valve stem part of the valve lifter in the form. shown in Fig. 4 iscomposed of a cap 3Q" and a materially fore-shortened plunger 33", thecap fitting partially within the cup-shaped member to be guided thereby.Projecting axially beyond the cap 3&3"- is a valve stem engaging boss35" while the inner face of the plunger is formed with a recess 36".This recess forms a seat for one end of a compression spring 3l", theother end of which abuts the bottom of the tubular extension 45 toseparate the parts of the valve lifter in the manner of and for the samepurpose as the spring 31 ln the form. shown in Fig. 2. Interposedbetween the cap 36" and the cupshaped member 28 to cushion the impact ofthe parts is an annular washer 38" like that shown in Fig. 2. Shims 39are preferably interposed between the washer 38" and the bottom of thecup-shaped member 28 to enable the clearance to be adjusted. Theunderneath surface of the cap 34" is again beveled to ease the impactand to insure separation of the cap from the washer 38".

It is believed readily apparent that the invention provides a simple andinexpensive means for .insuring quiet operation of the valve actuatingmechanism, and furthermore that it may be embodied in forms which ntinto existing valve actuating mechanism merely by the removal ofporrIhus in the forms illustrated in Figs. 2 and 4, the invention isadapted for injstallation in existing valve mechanism by remov` ing theadjusting screw and nut portions thereof and axing the invention to thestandard valve lifter parts 25 and 25". In the form illustrated in Fig.3, it is contemplated that the existing valve lifter part will becompletely replaced or that this form may be embodied in valvemechanisms when originally designed. It is, of course, contemplated thatvarious features of the invention may be embodied in original valvemechanism designed to obtain even further simplification. For example,the valve stem part 22 might readily be formed integrally with the Valvestem. i3.

By maintaining the valve stem and cam shaft parts of the presentinvention in continual contact with the valve stem and cam shaftrespectively, and providing a cushioning engagement between the parts,there will be no impact blows between two metal parts during theoperation of the mechanism as is the case in the present day valvemechanism wherein clearance is provided between the-upper end of thevalve lifter and thc valve stem.

By making the washers 38 with a contact area many times that of thelower end of the valve stem I3, the pressure per unit area on thecomposition washer is low enough so that the washer i Ato provideaccessibility for valve adjustment.

Since there are no screw devices used for adjusting the valves, shimsserving this purpose, the adjustment will be more permanent and willyeliminate the tight and loose valves nowadays caused by vibrationchanges of the screw device adjustments. Heretofore shims were-notpractical because of the small contact area of the valve lifter partslimiting the size of the shims so that the pressures encountered duringoperation would crushand destroy them, but the invention hereindisclosed, which increases the area to many times that of the valvestem, makes it possible to use thin metal shims for adjustment purposeswhen the valve mechanisms are initially installed.

Although the invention is herein illustrated and described in connectionwith an L-head type of engine, it is to be understood that the inventionin its various forms is equally suitablev forv use in connection withoverhead valve engines wherein the valve operating member 22 wouldengage the usual push rods of the valve mechanisms of such engines.Since overhead valve engines are well known in the art, it is notthought necessary to illustrate the valve actuating mechanism thereofherein. In overhead valveengines all adjustment screws and lock nutsusually furnished on the rocker arms will be eliminated just asadjusting'screws and lock nuts are eliminated in the valve mechanismillustrated.

I claim as my invention:

1. In an internal-combustion engine having a cylinder block, a cylinder,a port opening into the cylinder and a valve controlling the port, valvevactuating mechanism comprising a cam shaft and a valve lifterinterposed between the shaft and the valve comprising a tubular memberadapted to be operated by said cam shaft and guided for longitudinalreciprocatory movement, said member having an axial bore opening throughthe end remote from the cam shaft, a

In the form illustrated in cup-shaped member having a central apertureperiphery of the cup forming a hub for mounting the member on saidtubular member, a washer of heat and-oil resistant, resilientcomposition in said cup-shaped member and a plurality-of shimsinterposed between the bottom of said cup-shaped member and said washerto determine the position of the washer in the member, a valve operatingmember having a cylindrical portion slidable in the bore in said tubularmember and a disklike cap portion adapted to engage the washer to belimited thereby in im movement relative to the tubular member, saiddisk-like portion being beveled on its washer engaging face, and acompression spring disposed in the bore with one end abutting the end ofthe tubular member and the other end abutting the valve operating memberto maintain'the same respectively in engagement with the cam shaft andwith the valve.

2. In a valve lifter for valve actuating mechanism, a rst part having acup-shaped member at one end thereof, a second part mounted for jointmovement with said first part and for limited movement relative theretohaving an annular radial flange, the adjacent surface of which has theshape of the frustum of a cone having its apex toward said first part,and an annular washer of resilient material mounted in said cupshapedportion and having' a flat surface adapted to contact the frusto-conicalsurface of the ange progressively as the parts are moved toward eachother.

3. A silencer for valve actuating mechanism comprising, in combination,a rst member having a tubular portion insertable in the adjusting screwhole of a valve lifter and an enlarged annular iiange extendingoutwardly from the upper end ofsaid tubular portion and an uprightannular wall extending peripherally of said fiange to form a cup-shapedend, a plurality of shims positioned in said end, a member of syntheticresilient material positioned against said shims and within said wall, asecond member comprising a disk portion having its underneath surfacebeveled and in engagement with said member, an abutment on its othersurface for engagement with a valve stem, and a coil spring positionedwithin said tubular portion of said rst member and engaging the adjacentside of said second member for maintaining said members in contact withsaid valve lifter and valve stem respectively,

4. In a valve actuating mechanism for internal combustion engines, avalve lifter adapted to be interposed between the cam shaft of the en-.gine and the valve to be actuated comprising, a

first part adapted to be operated by the cam shaft having a depressionat the top thereof, a second part adapted to operate the valvecomprising a radially extending annular portion having a face at theside thereof opposite the first part and an axial central portionextending toward said first part, and an annular resilient membersupported in the depression comprising material yieldable under pressurehaving a face opposite the face on said second part and a centralaperture adapted to receive said axial central portion so as to serve asa cushioned guide for said axial portion, said faces being separatedfrom one another by distances increasing outwardly from the centralportion to provide upon the yielding of said member an area of contactvariable progressively in quantity during operation of the device.

5. A valve silencing device for insertion between avalve cam and valvestem of an internal combustion engine comprising, in combination, atubular member in contact with the cam having a cup-shaped upper end, anannular resilient member of substantial thickness confined radiallyentirely within said cup-shaped end, a plunger having a central portionreduced in cross section to form a stem extending within the centralaperture of the resilient member and laterally cushioned thereby, asubstantial elastic means in the tubular member in contact with theplunger adjacent the reduced end for urging said plunger in alongitudinal direction, said plunger having a flanged central portionprovided with a face adjacent the resilient member of a frustoconicalshape with the apex thereof in initial contact with said resilientmember adjacent the central aperture and adapted to provide an increasein contact area therewith in a geometric ratio as the pressure on saiddevice increases, and an upward extending portion on said plunger lncontact with the valve stem.

6. A valve actuating device for insertion between the cam shaft and thevalve of an internal vcombustion engine comprising a first memberadapted to be operated by the cam shaft and guided for longitudinalreciprocatory movement, said member having an axial bore opening throughthe end remote from the cam shaft, a cup-shaped member mounted on saidlast mentioned end of said rst member, an annular washer of heat and oilresistant resilient composition in said cup-shaped member, and aplurality of shims interposed between the bottom of said cup-shapedmember and said washer to determine the position of the Washer in thecupshaped member, a valve operating member having a cylindrical portionprojecting into the aperture in said annular washer to be guided therebyand a disk-like cap portion to engage the washer to be limited therebyin its movement rela-tive to the cup-shaped member, said disk-likeportion being beveled on its washer engaging face, and a compressionspring disposed intermediate said first member and said valve operatingmember toA maintain the same respectively in engagement with the camshaft and with the valve stem.

'7. A silencer forv valve actuating mechanism comprising, incombination, a first member having a cup-shaped end, a plurality ofshims positioned in said end, a member of synthetic resilient materialpositioned against said shims and within the cup-shaped end, a secondmember comprising a disk portion having its underneath surface beveledand in engagement with said resilient member and an abutment on itsother surface for engagement with a valve stem, and a coil springpositioned intermediate said first member and the adjacent side of saidsecond member for separating said members.

- OSCAR H. BANKER-

